package EPrints::Plugin::Export::REF_Excel;

use EPrints::Plugin::Export::REF;
@ISA = ( "EPrints::Plugin::Export::REF" );

use strict;

sub new
{
	my( $class, %opts ) = @_;

	my $self = $class->SUPER::new( %opts );

	$self->{name} = "REF2014 - Excel";
	$self->{suffix} = ".xls";
	$self->{mimetype} = 'application/vnd.ms-excel';

	my $rc = EPrints::Utils::require_if_exists('Spreadsheet::WriteExcel');
	unless ($rc)
	{
		$self->{advertise} = $self->{enable} = 0;
		$self->{error} = 'Unable to load required module Spreadsheet::WriteExcel';
	}
	
	$self->{advertise} = $self->{enable} = 1;
	
	return $self;
}


# Main method - called by the appropriate Screen::Report plugin
sub output_list
{
	my( $plugin, %opts ) = @_;

	my $output;
	open(my $FH,'>',\$output);

	my $workbook;
	if (defined $opts{fh})
	{
		binmode($opts{fh});
		$workbook = Spreadsheet::WriteExcel->new(\*{$opts{fh}});
		die("Unable to create spreadsheet: $!")unless defined $workbook;
	}
	else
	{
		$workbook = Spreadsheet::WriteExcel->new($FH);
		die("Unable to create spreadsheet: $!")unless defined $workbook;
	}

	$workbook->set_properties( utf8 => 1 );

	my $session = $plugin->{session};
	my $worksheet = $workbook->add_worksheet( $session->phrase( 'ref/report/excel:'.$plugin->get_report ) );

	# the appropriate REF::Report::{report_id} plugin will build up the list: 
	$plugin->{benchmark} = $opts{benchmark};

	my $institution = $session->config( 'ref', 'institution' ) || $session->phrase( 'archive_name' );
	my $action = $session->config( 'ref', 'action' ) || 'Update';

	# headers / field list
	my @cols = ("institution","unitOfAssessment","multipleSubmission","action", @{$plugin->ref_fields_order()} );
	my $col_id = 0;
	foreach my $col (@cols)
	{
		$worksheet->write( 0, $col_id++, $col );
	}

	# common fields/values
	my $commons = {
		institution => $institution,
		action => $action,
	};
	
	my $row_id = 1;

	# data...
	$opts{list}->map( sub {
		my( undef, undef, $user ) = @_;

		my $cols = $plugin->output_dataobj( $user, %$commons );
		return unless( scalar ( @$cols ) );

		my $col_id = 0;
		foreach my $col ( @$cols )
		{
			$worksheet->write( $row_id, $col_id++, $col );
		}
		$row_id++;
	} );

	$workbook->close;

	if (defined $opts{fh})
	{
		return undef;
	}

	return $output;
}

# Exports a single object / line. For CSV this must also includes the first four "common" fields.
sub output_dataobj
{
	my( $plugin, $dataobj, %commons ) = @_;

	my $session = $plugin->{session};

	return [] unless( $session->config( 'ref_enabled' ) );

	my $ref_fields = $plugin->ref_fields();

	my $objects = $plugin->get_related_objects( $dataobj );

	my @rows;
	my $uoa_id = $plugin->get_current_uoa( $dataobj );
	return [] unless( defined $uoa_id );	# abort!
	
	my ( $hefce_uoa_id, $is_multiple ) = $plugin->parse_uoa( $uoa_id );
	return [] unless( defined $hefce_uoa_id );

	my $valid_ds = {};
	foreach my $dsid ( keys %$objects )
	{
		$valid_ds->{$dsid} = $session->dataset( $dsid );
	}

	# first we need to output the first 4 fields (the 'common' fields)
	foreach( "institution", "unitOfAssessment", "multipleSubmission", "action" )
	{
		my $value;
		if( $_ eq 'unitOfAssessment' )	# get it from the ref_selection object
		{
			$value = $hefce_uoa_id;
		}
		elsif( $_ eq 'multipleSubmission' ) 
		{ 
			$value = $is_multiple || ""; 
		}
		else
		{
			$value = $commons{$_};
		}
		if( EPrints::Utils::is_set( $value ) )
		{
			push @rows, $plugin->escape_value( $value );
		}
		else
		{
			push @rows, "";
		}

	}

	# don't print out empty rows so check that something's been done:
	my $done_any = 0;
	foreach my $hefce_field ( @{$plugin->ref_fields_order()} )
	{
		my $ep_field = $ref_fields->{$hefce_field};

		if( ref( $ep_field ) eq 'CODE' )
		{
			# a sub{} we need to run
			eval {
				my $value = &$ep_field( $plugin, $objects );
				if( EPrints::Utils::is_set( $value ) )
				{
					push @rows, $plugin->escape_value( $value );
					$done_any++ 
				}
				else
				{
					push @rows, "";
				}
			};
			if( $@ )
			{
				$session->log( "REF_CSV Runtime error: $@" );
			}

			next;
		}
		elsif( $ep_field !~ /^([a-z_]+)\.([a-z_]+)$/ )
		{
			# wrong format :-/
			push @rows, "";
			next;
		}

		# a straight mapping with an EPrints field
		my( $ds_id, $ep_fieldname ) = ( $1, $2 );
		my $ds = $valid_ds->{$ds_id};

		unless( defined $ds && $ds->has_field( $ep_fieldname ) )
		{
			# dataset or field doesn't exist
			push @rows, "";
			next;
		}

		my $value = $objects->{$ds_id}->value( $ep_fieldname );
		$done_any++ if( EPrints::Utils::is_set( $value ) );
		push @rows, $plugin->escape_value( $value );
	}

	return [] unless( $done_any );

	return \@rows;
}

sub escape_value
{
	my( $plugin, $value ) = @_;

	return "" unless( defined EPrints::Utils::is_set( $value ) );

	# if value is a pure number, then add ="$value" so that Excel stops the auto-formatting (it'd turn 123456 into 1.23e+6)
	if( $value =~ /^\d+$/ )
	{
		return "=\"$value\"";
	}

	return $value;
}

1;